Efficiency of protein combinations in diets for Rhamdia quelen: growth, digestive and metabolic biochemistry and nutrient deposition.

This study was conducted to determine the best combination of protein sources in diets for jundiá, based on growth, metabolism, and nutrient deposition. Five protein combinations were tested: casein + fish meal (control), casein + gelatin, casein + albumin, casein + albumin + fish meal, and albumin + fish meal, in diets containing 370 g Kg-1 of crude protein and 13.4 MJ Kg-1 of digestible energy. The fish (9.38 ± 0.12 g) were allocated in a water recirculation system at a density of 3.35 g L-1 per experimental unit and fed until apparent satiety for 40 days with the diets. The fish fed with the control diet had the highest final weight, specific growth rate, protein and feed efficiency ratio, protein retention, and best apparent feed conversion. On the other hand, fish that received casein + albumin and albumin + fish meal diets showed worse results in growth and body protein retention, low trypsin and chymotrypsin activity, and high intestinal amylase activity. Therefore, the combination referred to as control (casein + fish meal) conclusively provides the best rhythm for nutrient digestion and metabolism processes, enabling fish to reach greater growth and retention of body protein with low whole-fish fat content.

Growth performance, plasma and hepatic biochemistry of jundiá Rhamdia quelen fed dephytinized rice bran protein concentrate.

A 45-day feeding assay was carried out to evaluate the effects of crescent levels of dephytinized rice bran protein concentrate (DRBPC) on growth performance, nutrient deposition, plasma and liver parameters of jundiá Rhamdia quelen. Five experimental diets were formulated with inclusion of 0 (control), 10, 15, 20, and 30% of DRBPC. In total 500 jundiás (initial body weight 6.28 ± 0.12 g) were allocated in 20 tanks (230 L) to give four groups for each treatment. Fish were fed to apparent satiation for 45 days. Weight gain and specific growth rate were evaluated by cubic regression analysis (P < 0.05) and displayed maximal growth on the inclusion level of 25% of DRBPC. The results indicated that fish fed DRBPC15 and DRBPC30 had lower body protein deposition and hepatosomatic index compared to CONTROL diet, respectively. No significant differences (P > 0.05) were assessed in plasma parameters. The alanine aminotransferase activity was higher in fish fed DRBPC30 compared to CONTROL group. The present study has demonstrated that DRBPC displayed significant nutritional quality for the jundiá. Thus, this new ingredient could be included as a protein source in fish for minimizing the use of fish meal.

Seasonal studies of aquatic humic substances from Amazon rivers: characterization and interaction with Cu (II), Fe (II), and Al (III) using EEM-PARAFAC and 2D FTIR correlation analyses.

Aquatic humic substances (AHS) are defined as an important components of organic matter, being composed as small molecules in a supramolecular structure and can interact with metallic ions, thereby altering the bioavailability of these species. To better understand this behavior, AHS were extracted and characterized from Negro River, located near Manaus city and Carú River, that is situated in Itacoatiara city, an area experiencing increasing anthropogenic actions; both were characterized as blackwater rivers. The AHS were characterized by 13C nuclear magnetic ressonance and thermochemolysis GC-MS to obtain structural characteristics. Interaction studies with Cu (II), Al (III), and Fe (III) were investigated using fluorescence spectroscopy applied to parallel factor analysis (PARAFAC) and two-dimensional correlation spectroscopy with Fourier transform infrared spectroscopy (2D-COS FTIR). The AHS from dry season had more aromatic fractions not derived from lignin and had higher content of alkyls moities from microbial sources and vegetal tissues of autochthonous origin, while AHS isolated in the rainy season showed more metals in its molecular architecture, lignin units, and polysacharide structures. The study showed that AHS composition from rainy season were able to interact with Al (III), Fe (III), and Cu (II). Two fluorescent components were identified as responsible for interaction: C1 (blue-shifted) and C2 (red-shifted). C1 showed higher complexation capacities but with lower complexation stability constants (KML ranged from 0.3 to 7.9 × 105) than C2 (KML ranged from 3.1 to 10.0 × 105). 2D-COS FTIR showed that the COO- and C-O in phenolic were the most important functional groups for interaction with studied metallic ions.

Economic analysis of banana peel and sweet potato vines in diets for rabbits.

This study aimed to evaluate the costs of using banana peel (BP) and sweet potato vine (SPV) in rabbit diets. BP and SPV were chosen to replace maize and alfalfa hay, because, in addition to the ingredients having similar nutritional characteristics, they are among the most expensive ingredients in rabbit diets. Data were obtained through a biological assay carried out in the Cuniculture Laboratory of the Universidade Federal de Santa Maria, Santa Maria, RS, Brazil. Fifty New Zealand white rabbits, weaned at 35 days of age, were fed during the growth phase (35 to 84 days) with increasing levels of BP and SPV, replacing maize and alfalfa hay (T0, T25, T50, T75 and T100% replacement). A diet containing 100% replacement (T100) had the lowest cost per kilogram, which was R$ 1.18/kg, while the controlled diet was 57% more expensive, costing R$ 2.08/kg. The total operating cost to produce a rabbit with control treatment was R$10.93/head and at T100, it was R$6.51/head. The animal income for a live rabbit was R$ 24.08 and R$ 23.95 in treatments T0 and T100, respectively. Regarding the gain margin per animal (GMA), in TO it was R$ 13.16 while in T100 it was R$ 17.44, therefore the GMA was 32.55% higher when using the T100 diet. In conclusion, it is more economical and feasible to feed rabbits with diets containing 100% BP and SPV, replacing maize and alfalfa hay.

Process development and characterization of recombinant nucleocapsid protein for its application on COVID-19 diagnosis.

COVID-19 pandemic was caused by the severe acute respiratory syndrome coronavirus 2 (Sars-CoV-2). The nucleocapsid (N) protein from Sars-CoV-2 is a highly immunogenic antigen and responsible for genome packing. Serological assays are important tools to detect previous exposure to SARS-CoV-2, complement epidemiological studies, vaccine evaluation and also in COVID-19 surveillance. SARS-CoV-2 N (r2N) protein was produced in Escherichia coli, characterized, and the immunological performance was evaluated by enzyme-linked immunosorbent assay (ELISA) and beads-based array immunoassay. r2N protein oligomers were evidenced when it is associated to nucleic acid. Benzonase treatment reduced host nucleic acid associated to r2N protein, but crosslinking assay still demonstrates the presence of higher-order oligomers. Nevertheless, after RNase treatment the higher-order oligomers reduced, and dimer form increased, suggesting RNA contributes to the oligomer formation. Structural analysis revealed nucleic acid did not interfere with the thermal stability of the recombinant protein. Interestingly, nucleic acid was able to prevent r2N protein aggregation even with increasing temperature while the protein benzonase treated begin aggregation process above 55 °C. In immunological characterization, ELISA performed with 233 serum samples presented a sensitivity of 97.44% (95% Confidence Interval, CI, 91.04%, 99.69%) and a specificity of 98.71% (95% CI, 95.42%, 99.84%) while beads-based array immunoassay carried out with 217 samples showed 100% sensitivity and 98.6% specificity. The results exhibited an excellent immunological performance of r2N protein in serologic assays showing that, even in presence of nucleic acid, it can be used as a component of an immunoassay for the sensitive and specific detection of SARS-CoV-2 antibodies.

Influence of COVID-19 on the notification of drug-resistant pulmonary tuberculosis cases.

BACKGROUND: To analyze the influence of the COVID-19 pandemic on the process of diagnosis and monitoring of drug-resistant pulmonary tuberculosis (TB) cases reported in the state of Paraná, Brazil, from 2015 to 2020. METHODS: Ecological study with quantitative approach. This study was based on diagnosed cases of pulmonary TB reported in the Notifiable Disease Information System in residents of Paraná; as well as through the number of confirmed cases of COVID-19 in the state epidemiological bulletin for the year 2020. The study data were analyzed using descriptive statistics. RESULTS: It was found that, although the number of reported pulmonary TB cases (drug-resistant and general) increased between 2015 and 2019, there was a drop in notification in 2020, the first year of the COVID-19 pandemic. The notification of TB cases was also influenced monthly during the year according to the increase in the number of COVID-19 cases. For cases of drug-resistant pulmonary TB, the provision of diagnostic tests and Directly Observed Treatment decreased by more than half in 2020, especially when compared to 2019. CONCLUSIONS: In view of these findings, the influence of COVID-19 on the diagnosis and monitoring of drug-resistant and general pulmonary TB cases is evident, showing that the pandemic has compromised the advances of recent decades in achieving the goals established for its eradication by 2035.

Can banana peel and sweet potato vines serve as efficient feed ingredients in diets for growing rabbits?

This study aimed to evaluate the use of banana peel (BP) and sweet potato vines (SPV) as a replacement for maize and alfalfa hay in diets for rabbits. Animal performance, economic analyses, meat composition, and color were evaluated for 49 days in a total 50 New Zealand White rabbits weaned at 35 days with an average body mass of ± 614 g. The animals were allotted, in a completely randomized design, having five dietary groups: control diet (0), without banana peels and sweet potato vines, or experimental diets, 25, 50, 75, and 100-with 25%, 50%, 75%, and 100% of banana peels and sweet potato vines in substitution to maize and alfalfa hay, respectively. The data were analyzed using ANOVA, while the means were compared by Tukey test (p < 0.05). The results indicate that daily feed intake, mass gain, and feed conversion were not statistically different from one another in the test groups compared to the control group treatment. In addition, the study shows no differences were observed in centesimal compositions and muscle color. The replacement of maize and alfalfa hay by the combination of BP and SPV resulted in reduction in feed costs, reaching 50% in the experimental diet with 100% of substitution the ingredients. It can be concluded, based on the results on animal performance, meat/color composition, and economic analyses, that BP and SPV may be used as a substitute for maize and alfalfa hay up to 100% in diets for growing rabbits.

Fractionation of linseed and obtaining ingredients rich in protein and fibers: alternatives for animal feed.

BACKGROUND: Linseed fractionation was performed in laboratory scale to obtain concentrated protein and fiber fractions. Three methods were tested to obtain the linseed protein concentrate (LPC). The isoelectric pH method was more efficient in increasing the protein content and also provided higher yield. In the fractions obtained, the chemical composition (dry matter, ash, lipids, crude protein, total dietary fiber, calcium and phosphorus), total phenolic compounds and the physicochemical properties were evaluated. The profile of amino acids was determined for linseed meal and LPC, and the profile of monosaccharides was evaluated for linseed grain, soluble and insoluble fractions of the fiber. RESULTS: The results indicated that the protein concentration method by isoelectric pH improved the amino acidic profile and in vitro digestibility of LPC. The fractioning of the linseed fiber was efficient, since the soluble fiber of the soluble fraction corresponded to 675 g kg-1 . The separation of the fiber from the linseed concentrated the phenolic compounds in the insoluble fraction. For linseed grain there was a higher concentration of glucose, followed by xylose, galacturonic acid and arabinose. The same monosaccharides were identified in the insoluble fraction, with the exception of arabinose. In the soluble fraction, higher levels of xylose were found, followed by glucose, galacturonic acid and arabinose. CONCLUSION: The present study allows us to conclude that it is possible to separate the linseed into different fractions, obtaining a protection concentrate and fibers. The inclusion of these products in animal feed needs to be evaluated to determine levels of acceptance. © 2021 Society of Chemical Industry.

Do chronic noncommunicable diseases modify the macronutrient composition of human milk?

This study aims to evaluate the impact of excess body weight, diabetes mellitus, and hypertension on the nutritional composition of human milk. This cohort study was conducted at a tertiary public health unit in the city of Rio de Janeiro from March 2016 to February 2018. The data were collected in two stages (96 hours and one month after delivery). The macronutrients (carbohydrate, protein, lipid) and total energy were determined using the MIRIS® equipment. The level of significance was 5%. Higher protein content was observed in the nutritional composition of colostrum in women with diabetes mellitus. A higher protein and energy content was observed in the milk of mothers with excessive body weight. The energy content was higher in the milk of mothers with excessive body weight. Increased protein content in the human milk of women with excessive body weight or diabetes.

Gestational weight gain and body composition of full-term newborns and infants: a cohort study.

BACKGROUND: The association between gestational weight gain and neonatal body composition has been inconsistent, exposing the need for further research. The aim of this study was to evaluate whether gestational weight gain influences the body composition of full-term newborns and infants up to 4 months old. METHODS: A cohort study was performed with 124 participants divided into categories of gestational weight gain according to the 2009 Institute of Medicine guidelines. The anthropometric and body composition data of newborns and infants acquired using air displacement plethysmography (PeaPod®) were collected at 96 h, 1 month, 2 months and 4 months of life. In the statistical analysis, the chi-square test was used to analyze categorical variables, and ANOVA was used to analyze numerical variables. Univariate analysis was performed, and the absolute and relative frequencies of the categorical variables, as well as mean and standard deviation of the numerical variables, were obtained. Bivariate analysis was performed for the categories of gestational weight gain and gestational and neonatal characteristics. When adjustments to gestational hypertension, gestational diabetes, and pregestational body mass index (BMI) were analyzed by linear regression, gestational weight gain remained a significant variable for newborn percent fat mass. For all analyses, a significance level of 5% was adopted. RESULTS: Gestational weight gain was adequate in 33.8% of the participants, excessive in 41.1% and insufficient in 25%. Women with excessive weight gain had higher pregestational BMIs and a higher incidence of gestational hypertension. Their newborns had a higher body mass, body fat mass in grams and percent fat mass than the infants born to mothers with adequate or insufficient gestational weight gain. No significant differences were observed in body composition at 1, 2 and 4 months of life during infant follow-up. CONCLUSION: Excessive gestational weight gain may alter the body composition of newborns at birth. Further studies are required to better evaluate infant follow-up. TRIAL REGISTRATION: Clinical Trial Registry: NCT00875251 on April 3, 2009.

Improving nutrient availability of defatted rice bran using different phytase sources applied to grass carp (Ctenopharyngodon idella) diet.

In the present study, we evaluated the effects of the hydrolysis of phytate of defatted rice bran (DRB) by a pretreatment with non-commercial phytase produced by Saccharomyces cerevisiae (DRB-PS) compared to the application of Natuphos® (commercial phytase produced by the BASF Company) (DRB-PN) in diets for grass carp, Ctenopharyngodon idella. Fish (57.55 ± 0.4 g) fed one of the experimental diets in triplicates for 35 days. Effects of the phytase used on blood parameters, intestinal proteases and hepatic glucose were not observed (p > 0.05). Similarly, no differences were found for serum phosphorus (P). However, were found higher levels of calcium (9 and 5.25%) in the control treatment in relation to DRB-PS and DRB-PN respectively, besides higher calcium-phosphorus ratio was found in this treatment. For the fish carcass composition was not statistically different (p > 0.05) except total lipids, which showed its highest content in fish fed on the DRB-PN diet (p < 0.05). The obtained results suggested that the use of the phytase, irrespective to its source may eliminate the use of traditional P sources in fish diets.

Linseed fibers modulate the production of short-chain fatty acids and improve performance and plasma and skin mucus parameters of silver catfish (Rhamdia quelen).

This study was conducted to evaluate the prebiotic action of distinct linseed fibers on diets for silver catfish (Rhamdia quelen) juvenile. For this, soluble and insoluble fractions of linseed fiber were concentrated separately and combined in four ratios (1:0.5, 1:1, 1:2, 1:4), which were added in diets and evaluated along with a control diet. After 45 days receiving the experimental diets, the animals were submitted to biometry for data collection and samples. The experimental design was completely randomized, data were submitted to analysis of variance, and the means were compared by Tukey's test (P < 0.05). Fish performance was higher for the group that received the 1:2 and 1:4 diets. The production of intestinal acetic acid was higher in fish fed on the 1:2 diet, and butyric acid was higher with 1:4 diet and the propionic acid with the control diet. The control diet led to lower counts of goblet cells. Total proteins and globulins in plasma, mucoprotein, total immunoglobulins, and cutaneous mucus pH were higher in fish fed on diets 1:2 and 1:4. Cortisol levels and intestinal pH were lower in these treatments. The linseed fiber intake increased total plasma immunoglobulins and plasma alkaline phosphatase activity and in mucus. It was concluded that the use of 1:2 and 1:4 soluble fiber/insoluble linseed in the diet beneficially modulates the production of short-chain fatty acids in the digesta, with reflection on growth performance, number of goblet cells in the intestinal epithelium, and improvement in plasma and skin mucus parameters of fish.

Performance, meat characteristics and economic viability of rabbits fed diets containing banana peel.

In developing countries, agricultural areas are used to grow ingredients for rabbits' nutrition instead of food for the human population. In this context, in places where people starve, it is unreasonable to use ingredients, such as maize, in rabbits' diets. This research aimed to evaluate performance, meat composition and coloration, and economic viability in rabbits fed with diets containing banana peel (BP) in substitution to maize. Forty-five White New Zealand rabbits were used; they were weaned at 35 days old and divided into five treatments in a completely randomized design. The animals were fed with some of the following diets: control diet (0BP)-without banana peel; experimental diets: 25BP, 50BP, 75BP and 100BP-with 25%, 50%, 75% and 100% of banana peel in substitution to maize, respectively. Means were compared through analysis of variance, followed by Tukey test (0.05). Results indicate there were no differences in performance and meat parameters. Banana peel inclusion resulted in lower costs. Therefore, banana peel can replace maize up to 100% in diets for rabbits with no loss in performance and meat composition, representing a promising alternative in rabbits' nutrition.

Deep RNAseq indicates protective mechanisms of cold-tolerant indica rice plants during early vegetative stage.

KEY MESSAGE: Cold-tolerance in rice may be related to increased cellulose deposition in the cell wall, membrane fatty acids unsaturation and differential expression of several newly identified genes. Low temperature exposure during early vegetative stages limits rice plant's growth and development. Most genes previously related to cold tolerance in rice are from the japonica subspecies. To help clarify the mechanisms that regulate cold tolerance in young indica rice plants, comparative transcriptome analysis of 6 h cold-treated (10 °C) leaves from two genotypes, cold-tolerant (CT) and cold-sensitive (CS), was performed. Differentially expressed genes were identified: 831 and 357 sequences more expressed in the tolerant and in the sensitive genotype, respectively. The genes with higher expression in the CT genotype were used in systems biology analyses to identify protein-protein interaction (PPI) networks and nodes (proteins) that are hubs and bottlenecks in the PPI. From the genes more expressed in the tolerant plants, 60% were reported as affected by cold in previous transcriptome experiments and 27% are located within QTLs related to cold tolerance during the vegetative stage. Novel cold-responsive genes were identified. Quantitative RT-PCR confirmed the high-quality of RNAseq libraries. Several genes related to cell wall assembly or reinforcement are cold-induced or constitutively highly expressed in the tolerant genotype. Cold-tolerant plants have increased cellulose deposition under cold. Genes related to lipid metabolism are more expressed in the tolerant genotype, which has higher membrane fatty acids unsaturation, with increasing levels of linoleic acid under cold. The CT genotype seems to have higher photosynthetic efficiency and antioxidant capacity, as well as more effective ethylene, Ca2+ and hormone signaling than the CS. These genes could be useful in future biotechnological approaches aiming to increase cold tolerance in rice.

Integrated biomarkers response confirm the antioxidant role of diphenyl diselenide against atrazine.

Atrazine (ATZ) is a herbicide worldwide used. That can cause oxidative damage in non-target organisms, such as fish. Furthermore, the threat of exposure to pesticides together with poor nutrition is hazardous to the normal development of fish, and supplementation of the fish diet with antioxidants compounds is an alternative approach to prevent the hazardous effects of pesticide exposure. Here we aimed to investigate the capacity of diphenyl diselenide (PhSe)2 diet supplementation to improve the antioxidant defense of Cyprinus carpio (carp) exposed to environmental concentrations of ATZ. To prove the efficiency of (PhSe)2, we used the Integrated Biomarkers Response (IBR) methodology. Therefore, carp were fed for 8 weeks diets either with or without (PhSe)2 and exposed to 2 or 10µg/L of ATZ for 96h, euthanized, and their liver, gills, and muscle tissues were removed for biochemical assays. ATZ was able to cause oxidative damage from reactive species production in all tissues of carp, as observed by the increase of lipid peroxidation and protein damage. The activity of some antioxidant enzymes was inhibited in carp exposed to ATZ. However, (PhSe)2 supplementation was able to prevent this ATZ-induced damage by improving the activities of antioxidant enzymes and through antioxidant competence of (PhSe)2per se. Furthermore, IBR was shown to be a useful tool to compare treatments, even at different concentrations, and identify the efficiently antioxidant behavior of the organoselenium compound.

Sunflower protein concentrate and crambe protein concentrate in diets for silver catfish Rhamdia quelen (Quoy and Gaimard, 1824): use as sustainable ingredients.

The objective of this study was to evaluate growth and metabolic parameters of silver catfish fed with protein concentrates of sunflower meal (SMPC) and crambe meal (CrMPC). The study evaluated two levels of substitution, where 25 or 50% of animal protein was replaced with plant-based protein. A total of 300 silver catfish (14 ± 0.26 g) were used in five treatments and three replications, in fifteen 280-liter experimental units. The results were submitted to analysis of variance and the means of the control diet was compared to the remaining treatments by Dunnett's test at 5% significance level. At the end of the trial, no differences were observed for the variables final weight and daily weight gain. However, minor feed conversion was observed in the groups Control and SMPC-25%. Metabolic parameters were analyzed in the plasma and liver, where no significant differences were found for any of the blood parameters analyzed. In the analyzed liver parameters (ammonia, protein, amino acids and ALAT), the liver protein content was lower in fish consuming SMPC-50%, CrMPC-50% and 25% CrMPC diets. The amino acids content was higher in fish receiving the SMPC-25% diet. It can be concluded that sunflower meal protein concentrate is better utilized by fish and more efficient metabolically than crambe meal. This study demonstrated that a newly developed protein concentrate SMPC and CrMPC can effectively replace 25% and 50% the animal protein in a diet free of FM.

Effects of dietary microencapsulated Cymbopogon flexuosus essential oil on reproductive-related parameters in male Rhamdia quelen.

In aquaculture, nutrition and supplemented diets have been shown to affect broodstock reproductive performance. In this study, we investigated the effects of dietary supplementation with Cymbopogon flexuosus essential oil (CFEO) microcapsules on reproductive-related parameters in silver catfish (Rhamdia quelen) male broodfish. Adult male broodstocks were separated into three groups according to the concentrations of supplemented CFEO (0.0 = control; 1.0 or 3.0 mL per kg of diet). After 20 days under experimental conditions, the animals were euthanized and the gonads were harvested for gonadosomatic index, sperm analysis, oxidative stress, and histopathology; testosterone levels were measured in the plasma; gene expression of prl, smtl, pomca, and pomcb was assessed in the pituitary gland by real-time PCR. The results showed no alterations on reproductive parameters in R. quelen males treated with Cymbopogon flexuosus essential oil compared to the control-diet animals. In conclusion, CFEO microcapsules supplied for 20 days in the concentrations of 1.00 or 3.00 mL per kilogram of diet did not affect the reproduction criteria evaluated in this study in male silver catfish.

Cervical cancer prevention among quilombola women in the light of Leininger's theory. / Prevenção do câncer do colo uterino de quilombolas à luz da teoria de Leininger.

OBJECTIVE Our purpose was to discuss practices of cervical cancer prevention among Quilombola Women. METHOD This study used, in 2014, a qualitative research approach aiming twenty women from a quilombola community (people who live in quilombos, descendants of Afro-Brazilian slaves), which is located in Bahia. A semi-structured interview was developed by researchers in order to collect data. The Ethno-nursing Research method was used to analyze the data. RESULTS The use of cultural care through medicinal plants, and the nursing professional care (Pap Smear exam procedure) were stated by Quilombola women as serving as prevention practices against cervical cancer. However, most women stated that they did not use any prevention practices. CONCLUSION Social, cultural and health access issues are practices that are linked to the cervical cancer prevention among Quilombola Women. Therefore, it is indispensable to create an appropriate care plan for Quilombola women's reality.

Crambe (Crambe abyssinica) and sunflower (Helianthus annuus) protein concentrates: production methods and nutritional properties for use in fish feed.

The purpose of this study was to develop and improve protein concentration techniques for two industrial by-products with the potential for use in fish feed. In particular, we chemically characterized crambe meal and sunflower meal and their protein concentrates. Three different protein concentration methods were tested: isoelectric pH (pHi), acid pH and alkaline pH. For crambe and sunflower meals extraction using the pHi method was most efficient in terms of protein yield and crude protein content in the concentrates; this method also increased lysine and methionine content in the concentrates. The water holding capacity of the sunflower protein concentrate was greater than that of the crambe protein concentrate. The crambe protein concentrate had a foam-formation capacity of 15%, which stabilized at 6% after 90 minutes. The protein concentration method also reduced total phenolic content by approximately 50% in the concentrates compared with the meals. Therefore, we conclude that protein concentration using the pHi method is the most efficient technique for crambe and sunflower meals, and the use of this technique can decrease total phenolic compounds while improving meal quality for fish feeding.

Characterization and physicochemical properties of pectins extracted from agroindustrial by-products.

The composition and fine structure of pectins found in plant cell walls are heterogeneous, with striking differences, depending on their source, and this eventually determines their functional and technological properties. The aim of this study was to extract and determine the chemical composition and physicochemical properties of pectins from different sources: passion fruit peel, orange pomace, and soy hull. Pectin extraction was performed with heated hydrochloric acid solution, followed by precipitation with 96% ethanol. Extraction yield, chemical composition, molar mass, physicochemical properties (fat absorption capacity, cation exchange capacity, water holding capacity, and antioxidant activity) of pectin were measured. Pectin extraction efficiency was higher for passion fruit peel and orange pomace (15.71 and 17.96%, respectively). Soy hull had low pectin extraction (5.66%). Galacturonic acid content was 23.21% for passion fruit peel pectin and 16.01% for orange pomace pectin. Water holding capacity, fat absorption capacity, and cation-binding capacity present in pectin extracted from passion fruit peel were higher, suggesting this poorly investigated product could be used as thickening and emulsifying agents in food preparations. Phenolic compounds with antioxidant capacity provide pectins with additional properties and expand their industrial use.